Incandescent light bulbs or lamps are often capable of producing different levels of illumination. For example, conventional three-way incandescent lamps are often capable of producing light at three different intensities. As a specific example, conventional three-way incandescent lamps typically include two different filaments, such as a fifty watt filament and a one hundred watt filament. A conventional three-way incandescent lamp is typically inserted into a base structure that includes two switches, each switch capable of connecting one of the filaments to a power supply. Different combinations of opened and/or closed switches may produce light outputs of fifty watts from the first filament, one hundred watts from the second filament, or one hundred fifty watts from both filaments.
This type of base structure is typically not suited for use with conventional fluorescent lamps. Typical fluorescent lamp bases or “ballasts” operate by rectifying alternating current (“AC”) inputs and then using a high frequency inverter to drive fluorescent tubes. As a result, a conventional base structure that uses different switches to connect a fluorescent lamp to a power supply would be incapable of altering the light intensity produced by the fluorescent lamp. This is due to the fact that the AC inputs would be rectified and the same inverter would drive the fluorescent lamp regardless of the switch settings.